Description and distribution of three morphotypes of the Eucyclops serrulatus group (Crustacea, Copepoda, Cyclopoida) from Algerian water bodies

Biodiversity Data Journal 11: e100981 OO)
doi: 10.3897/BDJ.11.e100981 open access
Taxonomy & Inventories

Description and distribution of three morphotypes
of the Eucyclops serrulatus group (Crustacea,
Copepoda, Cyclopoida) from Algerian water bodies

Safia Akli-Bidi +

+ Department of Ecology and Environment. Laboratory of Dynamic and Biodiversity. Faculty of Biological Sciences. University
of Sciences and Technology Houari Boumediene.,. Algiers. Algeria., Bab Ezzouar, Algeria

Corresponding author: Safia Akli-Bidi (safiabidi@yahoo.fr)

Academic editor: Diana Galassi

Received: 24 Jan 2023 | Accepted: 21 Feb 2023 | Published: 02 Mar 2023

Citation: Akli-Bidi S (2023) Description and distribution of three morphotypes of the Eucyclops serrulatus group
(Crustacea, Copepoda, Cyclopoida) from Algerian water bodies. Biodiversity Data Journal 11: e100981.
https://doi.org/10.3897/BDJ.11.e100981

Abstract

Background

Examination of Eucyclops populations coming from Algerian water bodies and identified as
Eucyclops cf. serrulatus showed three morphotypes, based on morphometric characters
and microcharacters. Morphotype 1 was the most abundant, collected in the east and the
west of Algeria. Morphotype 2 was sampled in the south of the country, characterised by
posterolaterally elongated thoracic segments and the fourth thoracic segment bearing cilia
on its lateral angles. Morphotype 3 was found in a small temporary pond in the north of the
country and was the smallest one. Other differences were observed on _ surface
microcharacters of antenna basipodite, coxopodite and intercoxal plate of the fourth leg.
The characters of the most widespread morphotype (morphotype1) were stable in all
localities despite the fact that these were located in two geographically separated regions
(eastern and western Algeria).

© Akli-Bidi S. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

2 Akli-Bidi S

New information

Three morphotypes of Eucyclops serrulatus group (Fisher, 1851) (Crustacea, Copepoda,
Cyclopoida) from Algerian water bodies were identified. The characters of the most
widespread morphotype (morphotype 1) were stable in all localities despite the fact that
these were located in two geographically separated regions (eastern and western Algeria).

Keywords

distribution, Eucyclops serrulatus group, morphotypes, morphometrics, microcharacters

Introduction

The genus Eucyclops (Copepoda, Cyclopoida) comprises about one hundred species and
15 subspecies (Dussart and Defaye 2006, Alekseev and Defaye 2011, Mercado-Salas and
Suarez-Morales 2014). The last revision of the whole genus was done by Lindberg (1957)
for African Eucyclops. Several revisions of Eucyclops were published: for Australia by
Morton (1990), for Ukraine by Monchenko (1974), for Japan by Ishida (2002), for Mexico
by Mercado-Salas and Suarez-Morales (2014) and for Palearctic by Alekseev and Defaye
(2011) and Alekseev (2019). The serrulatus group of the cyclopid freshwater genus
Eucyclops comprises species having 12-segmented antennules with the three most distal
segments possessing a smooth hyaline membrane, caudal rami 3.5-7 times as long as
wide with a longitudinal row of spinules along most of the outer edge of each ramus, a
strong inner spine on P5 and a number of microcharacters presented on the antennary
basipodite and the caudal surface of P4 coxopodite, as described by Alekseev and Defaye
(2011). The type species of this genus is Eucyclops serrulatus (Fischer, 1851). This
species has been reported from waterbodies around the world (Dussart and Defaye 1985,
Dussart and Defaye 2006) and, consequently, it has long been considered a cosmopolitan
species until some species that look like Eucyclops serrulatus were separated from it
(Dussart 1984, Reid 1995, Ishida 1997, Ishida 1998). Some of these may indeed be valid
species; others were forms of Eucyclops serrulatus. Considerable interpopulation variability
in E. serrulatus was described; some of them are cryptic taxa and need to be revised
(Sukhikh and Alekseev 2015). Eucyclops serrulatus has been observed in the samples
collected in Algeria in the Hoggar, south of Tassili n’Ajjer, in Tamanrasset and in Guelma
(Roy and Gauthier 1927). The re-description of the type for Eucyclops serrulatus (Alekseev
et al. 2006) using molecular-techniques revealed several microcharacters, important for the
species identification as ornamentation of antennary (A2) basipodite and the fourth leg (P4)
coxopodite with coxal spine. The name ‘serru/atus group’ is used for the E. serrulatus
species complex and it was established by Kiefer in 1928 for a group of tropical species
closely related to E. serrulatus (Alekseev and Defaye 2011). The serrulatus group now
includes 17 species and subspecies, which differ from each other in the presence of
microcharacters of the antennary basipodite and the P4 coxopodite. The aim of this work is

Description and distribution of three morphotypes of the Eucyclops serrulatus ... 3

to describe and compare Algerian morphotypes of Eucyclops serrulatus group coming from
different localities.

Materials and methods

Several water bodies were sampled in different regions in Algeria. Eucyclops cf. serrulatus
(Fischer, 1851) was found in 21 localities (Fig. 1, Table 1). All samples were collected by
horizontal trawl at 1 m depth in the near-shore areas using standard plankton net of 50-um
mesh size. Samples were collected by the author. The samples were preserved in 70%
ethanol. For the measurements, six females of each population collected from the field
were first placed in small Petri dish containing a mixture of alcohol, water and glycerine.
Once the water evaporated (1-2 days), body length, relative length of antennules, the
fourth and fifth legs and caudal rami were measured (Table 2). The specimens were
dissected in concentrated glycerine and put between slide and coverslip in a drop of
glycerol. The measurements and the drawings were made using a drawing tube attached
to the microscope. The morphotypes were described, based on the habitus and the
microcharacters: the ornamentation of antennule (A1) and antennary (A2) basipodite,
caudal surface ornamentation of P4 coxopodite and intercoxal plate, using the coding
system for microcharacters in Eucyclops proposed by Alekseev et al. (2006).

Table 1.

Occurrences of Eucyclops cf. serrulatus morphotypes in different localities (numbers referred to the
localities).

Eucyclops cf. Localities with occurrences of the three morphotypes
serrulatus

Morphotype 1 (1) Females; (2) Males, females; (3) Females; (4) Males, females; (5) Several males, several
females; (6) Females; (7) Males, females; (8) Males, females; (9) Females; (10) Males, females;
(11) Males, females; (12) Males, females; (13) Females; (14) Several males, several females;
(15) Males, females.

Morphotype 2. = (16) Several male: Several females; (17) Several males, several females; (18) Several males,
several females; (19) Several males, several females; (20) Several males, several females.

Morphotype 3 = (211) Males, females.

Table 2.

Female morphometric characters in morphotypes of Eucyclops cf. serrulatus.

Eucyclops cf. serrulatus Morphotype 1 Morphotype 2 Morphotype 3
range mean range mean range mean
(mm) (mm) (mm)

Body length (mm) 0.86 -1 0.93 0.81- 0.93 0.79-1 0.85

Cephalothorax, length / width 1-1.2 1.08 1-1.2 1.06 1-1.18 1.05

Eucyclops cf. serrulatus
P5, length of outer seta / length of spine
Caudal rami, length / width

Caudal rami, length of innermost setae/length of

outermost spine like seta

P4 Enp3, length / width

P4 Enp3, inner apical spine /outer apical spine
P4 Enp3, inner apicalspine / segment length

Genital segment: length / width

“
© Mediterranean sea

Zeralay ES

15 Rids

£ Niedea

Mostaganem

ss Tesgqmailt

Traret Hassi bahbah

El Bavadh

1
El Abioanh Sidi
Cheikh

17, 15 Pgs

18

Figure 1. EES]

Cc enet
apd) =

Bou:ra
Bord; bow Arrundy

Akli-Bidi S

Morphotype 1
0.98-1 0.97
444 4.2

0.8-1 0.93

2.5-3 2.8
1.3-1.5 1.36
1.5-1.6 1.55

1.1-1.2 1.15

Jel
Bejaia =

Jjurdéjire*

Bidet Amor

Morphotype 2
0.98-1 0.97
4.5-5 4.76

1.3-1.6 1.46

2.3-2.9 | 2.6
1.3-1.4 1.33
0.98-1 0.96

1.1-1.3 1.14

Constantiney

6

Morphotype 3
0.97-1.2 1.05
3.5-4.2 3.96

1.4-1.5 1.48

2.4-2.7 2.6
1.3-1.4 1.38
0.99-1 0.98

1-1.1 0.95

Mapping of sampling localities (numbers referred to localities) for morphotypes of Eucyclops
cf. serrulatus (Fischer, 1851). Morphotype 1: (1-15); morphotype 2: (16-20); morphotype 3:

(21).

Taxon treatment

Eucyclops cf. serrulatus Fisher, 1851

Nomenclature

Synonymy in Dussart and Defaye (1985)

Cyclope serrulatus, Fischer, 1851

Description and distribution of three morphotypes of the Eucyclops serrulatus ...

Eucyclops serrulatus, Claus, 1893a

Cyclope agilis, Gurney, 1933

Eucyclops agilis, Comita, 1951

Eucyclops serrulatus, Dussart, 1969; Kiefer, 1978
Synonymy in Dumont (1979)

Eucyclops asymmetricus, Dumont and Pensaert, 1979

Materials

a. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 1-Terni wadi (Tlemcen); verbatimElevation: 867 m; verbatimCoordinates:
34°47'45"N 01°21'32"W; sex: Females; occurrence!D: 426BOCAF-F32A-51D1-ACE2-
BA77EFA869A6

b. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 2.Tafna source(Tlemcen); verbatimElevation: 867 m; verbatimCoordinates:
34°39'48"N 01°20'02"W; sex: Males, Females; occurrence!D: 442B1B63-
FB26-5124-99CF-685A20325890

C. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 3. Saida wadi (Saida); verbatimElevation: 980 m; verbatimCoordinates:
34°55'0"N, 0°13'0"W; sex: Females; occurrence!D: 31CE7192-D47F-54C0-8366-
D22EFED3264F

d. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 4.Chellif wadi (Ech Chellif); verbatimElevation: 86 m; verbatimCoordinates:
36°02'22"N 0°07'55"E; sex: Males, Females; occurrence!D: 32E56668-
AD2A-58A7-8C78-5BE0D8305EAA

e. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 5. Basins of Djurdjura (Bouira); verbatimElevation: 2308 m; verbatimCoordinates:
28°00N 03°00E; sex: Males, Females; occurrence!lD: 3EAF7316-
D209-5E3D-829B-27F274092B92

f. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 6.Rhumel wadi (Constantine); verbatimElevation: 1090 m; verbatimCoordinates:
36°32'17"N 1°15'59"E; sex: Females; occurrence!D: 890E0C23-240C-5743-
BE15-017B39EDE754

Akli-Bidi S

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 7. Boumerzoug wadi (Constantine); verbatimElevation: 506 m;
verbatimCoordinates: 36°21'3"N 06°37'2"E; sex: Males, Females; occurrencelD:
1080AA15-4DAB-5C27-8C38-0D9A25A48EF2

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 8. Benazouz wadi (Skikda); verbatimElevation: 17 m; verbatimCoordinates:
35°27'0"N 03°51'0"E; sex: Males, Females; occurrence!D: 5D2B1234-2603-5E8E-B3D7-
FBOC4D729FF9

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 9. Seybouse wadi (Annaba); verbatimElevation: 0 m; verbatimCoordinates:
36°52'01"N 07°46'18"E; sex: Males, Females; occurrence!D:
22BE37AC-5089-530A-9ADC-CCE8EC01C51A

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 10. Lake of Oubeira (El Taref); verbatimElevation: 25 m; verbatimCoordinates:
36°50'695 N 8°23'272 E; sex: Males, Females; occurrence!D:
481FB5C6-96E0-57A0-97DC-660499B898B6

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 11. Lake of Tonga; verbatimElevation: 589-1061 m; verbatimCoordinates:
36°51'511 N 8°30'100 E; sex: Males, Females; occurrence!|D: 2D38EC65-8DF5-5AEB-
A6E7-7CD09C57A3F 1

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 12. Blue lake (El Taref); verbatimElevation: 1-123 m; verbatimCoordinates:
36°31'60" N 07°40'0" E; sex: Males, Females; occurrence!D: 251DAD60-F172-5E97-
AFA6-CE64E09174E8

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 13. Messida wadi; verbatimElevation: 1 m; verbatimCoordinates: 36°54'0" N
08°31'0" E; sex: Males, Females; occurrence!D: CBF843B7-5FB2-550F-9AB7-
B9OFAA949BDB1

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 14. Basins (Tasslemt, Tissemssilt); verbatimElevation: 900 m;
verbatimCoordinates: 35°36'00,00” N 1°49'00,00” E; sex: Males, Females; occurrence!D:
6616E321-7046-5F CO-BODC-FE94C8D3CB7A

scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;

Description and distribution of three morphotypes of the Eucyclops serrulatus ... 7

continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 15. Basins (Tamezguida,Medea)”; verbatimElevation: 591 m;
verbatimCoordinates: 36°19'27" N 02°41'22” E; sex: Males, Females; occurrence!D:
F9C0C57B-BCEC-519D-9941-E3A2B25962F3

p. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 16.Seggerwadi(Biskra); verbatimElevation: 87 m; verbatimCoordinates: 34°0'0"N
5°0'0"E; sex: Males, Females; occurrence!D: 584E7A11-5DB1-5277-BDD9-
F255530B0F 53

q. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 17. Lake of Ain Saadane (EI Biodh Sidi Cheich); verbatimElevation: 744 m;
verbatimCoordinates: 32°53'55" N 0°32'22" E; sex: Males, Females; occurrencelD:
B4824273-01D1-5C1D-85A2-41A11DDE507F

lf scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 18. Source of Ain EL Hammam (Brezina-); verbatimElevation: 849 m;
verbatimCoordinates: 33°05'58”" N 1°15'39" E; sex: Males, Females; occurrencelD:
A26C75B4-6981 -5E00-BAB5-6B30B87D624B

S. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 19. Lake of Gue of Arsaouet (El Biodh Sidi Cheich); verbatimElevation: 744 m;
verbatimCoordinates: 32°53'55" N 0°32'22" E; sex: Males, Females; occurrencelD:
46698A17-EB7C-5612-AB1C-205B7AC50B79

t. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 20. Source of El Goleita (Brizina); verbatimElevation: 849 m;
verbatimCoordinates: 33°05'58” N 01°15'39" E; sex: Males, Females; occurrencelD:
3486980E-0645-5530-9F 9D-48E53F ED8E68

u. scientificName: Eucyclops cf. serrulatus; class: Copepoda; family: Cyclopidae; genus:
Eucyclops; scientificNameAuthorship: Fisher, 1851; higherGeography: North Africa;
continent: Africa; waterBody: Freshwater; country: Algeria; countryCode: Algeria/DZ;
locality: 21. Swamp (El-Harrach, Algiers); verbatimElevation: 0-178 m;
verbatimCoordinates: 36°43'16"” N 03°08'15" E; sex: Males, Females; occurrence!D:
A653531E-391F-5513-B8FF-94E1506DF9EA

Description

Based on habitus, morphotype 3 of Eucyclops serrulatus group was the smallest one
(Table 2), morphotype 1 is characterised by external articulation of its abdominal
segments (Fig. 2a), while morphotype 2 is identified by its elongated lateral thoracic
segments which envelop the following segment and its fourth thoracic segment has
cilia on its lateral angles (Fig. 4a).

Akli-Bidi S

Figure 2. EES]
Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 1; a Habitus (dorsal view); b caudal rami;
c A1; d A2 basipodite (posterior surface); e A2 basipodite (anterior surface).

Oe at
NW \, Stee

~— AY
a ca = oe,
5 ‘ \ ¥ ant
{ t { \ . \\\\\ \
\ Ys c
| \ 4 Syl Meg
"e) f 4 peed S. wat Qe sti'senerat
LA_t_A___— — Saeed
$0um SOum
c) CEQ

Figure 3. EES
Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 1

a first leg (P1) with coxopodite and intercoxal plate (with fine denticules), arrow show external
seta of exopodite 3 with a row of little spinules along outer margin and with setules on inner
edge; b fourth leg (P4) with coxopodite and intercoxal plate, arrows showing two apical setae

of exopodite 3 stylet-shaped; c fifth leg (P5).

Description and distribution of three morphotypes of the Eucyclops serrulatus ...

Figure 4. EES]

Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 2; a habitus (dorsal view); b caudal rami;
c A1 basipodite; d A2 basipodite (posterior surface); e A2 basipodite (anterior surface).

ay SS a Hil
| |
~ 4 | !
— |
SN ~~ \
2
~—_, y> \ \ \ wl, /
= a
“= G i) : )
) 5
lV
to AY 4
we C+D = LY, y / Z,
ea 7
SOum wt Yyk
Figure 5. EES]

Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 2; a first leg (P1) with coxopodite and
intercoxal plate, arrow showing external seta of exopodite 3 with a row of little spinules along

outer margin and with setules on inner edge; b fourth leg (P4) with coxopodite and intercoxal
plate; c fifth leg (P5).

10

Akli-Bidi S

} c)
ba
Prey Ar) es
—_ : ‘
K if { y “
/ ; os 50um
| ) ‘ ia wh href \ ie %
| | I \N\ { \y e)
nt fA\\' K At \ d) 7 | -_
|] PANY \ vHi/ $ id Y j
AY k NG \ r uf J
yi f WAN JA Fa
\ NS AWN a
i} \VT { 7
f} aN):
fy \ \
} t 50um y \
a = (ae)
— Mun :

Figure 6. EESl

Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 3; a habitus (dorsal view); b caudal rami;
c A1 basipodite; d A2 basipodite (posterior surface); e A2 basipodite (anterior surface).

P5 with a spine as long as outer seta in all morphotypes, slender and long in
morphotypes 1 and 3 (Fig. 3c, Fig. 7c) and large in morphotype 2 (Fig. 5c).

%
~AN \ \ | \
a #
a b \\ # |
a) Se \ ) | \ My h |
~ \\\ 4A
1 EM | My)
= | \ | f
ahh “SK lA / \ | if
Ne fh iy ij
Ef ) YW / er
as, MA A | Va
Mr, sy) Lil N_ ff h §
¥ f } " 7
—atts \ } Bes Naud / Va
= we MA j \ |
\, -
y F f A Ky type
a / DS > y
‘\ i
t
SOum
c) ra ;
Al
iy
iy ri
Fd \\
f y
Suen

Figure 7. EESl

Eucyclops cf. serrulatus (Fischer, 1851). Morphotype 3; a first leg (P1) with coxopodite and
intercoxal plate, arrow showing external seta of exopodite 3 with a row of little spinules along
outer margin and with setules on inner edge; b fourth leg (P4) with coxopodite and intercoxal

plate; c fifth leg (P5).

Description and distribution of three morphotypes of the Eucyclops serrulatus ... 11

Caudal rami somewhat divergent: morphotype 1:4—4.5 times longer than wide (Fig. 2b),
morphotype 2:4.5—5 times longer than wide (Fig. 4b), morphotype 3:3.5—4 times longer
than wide (Fig. 6b). Serra (longitudinal row of spinules) with 51 denticules in
morphotype 1, 28 denticules in morphotype 2 and 22 denticules in morphotype 3,
spine-like outermost seta with spinules along outer margin and long setules on inner
edge in all the morphotypes. Innermost seta with long setules on both sides, about 1.3—
1.4 times longer than spine-like outermost seta in morphotypes 2 and 3, but almost
equal in morphotype 1.

Antennule 12-segmented, reaching middle of first free thoracal somite in morphotypes
1 and 2 and the beginning of the third one in morphotype 3 (Fig. 2a, Fig. 6a), the last
three articles with hyaline membrane, the first segment with curved row of spinules at
its base; outermost spinules the longest in morphotypes 1 and 2 (Fig. 2c, Fig. 4c). In
morphotype 3, the longest ones were between two groups of little spines (Fig. 6c).

Antennary basipodite, posterior face: (N1) with three long setules in morphotypes 1 and
3 (Fig. 2d, Fig. 6d), five long setules in morphotype 2 (Fig. 4d); a group of two long
spinules (N6) and three diagonal and parallel rows of spinules (N3-5) only in
morphotype 1.

Antennary basipodite, anterior face: (N8) composed of three long spinules subdistally
in morphotype 1 (Fig. 2e), five long spinules subdistally in morphotype 2 and three (Fig.
4e, Fig. 6e), (N11 + N12) formed of a long row of relatively small spinules with 17
spinules in morphotype 1, 13 spinules in morphotype 2. In morphotype 3 only (N11)
exist with eight spinules, (N13) represented by a group of five little spinules only in
morphotype 1, two groups of marginal spinules (N17) and (N15) only in morphotypes 1
and 2, in morphotype 3 only (N17) exist.

Endopodite and exopodite segments of P1—P4 were plumose.

P1: inner edge of basipodite with group of long hair only in morphotypes 1 and 2 (Fig. 3
a, Fig. 5a), intercoxal plate with two groups of finest spinules on body of protuberances,
only in morphotype 1, external seta of exopodite 3 in all morphotypes with a row of little
spinules along outer margin and with long setules on inner edge (Fig. 3a, Fig. 5a, Fig. 7
a).

P4, innermost apical spine of endopodite 3 was 1.3—1.4 times as long as outermost
apical spine in all morphotypes and about 1.5-1.6 times as long as supporting segment
in morphotype 1 (Fig. 3b) and as long as supporting segment in morphotypes 2 and 3
(Fig. 5b, Fig. 7b), outer seta long reaching almost the top of outermost apical spine in
all morphotypes, two apical setae of exopodite 3 stylet-shaped only in morphotype 1
(Fig. 3b), inner edge of basipodite with group of long setules only in morphotypes 1 and
3 (Fig. 3b, Fig. 7b). Coxopodite with a row of numerous fines spinules along internal
distal side only in morphotype 1, several groups of spinules: (A — B - (C + D) —E-G-H-l)
in morphotype 1, (A — B- (C + D) —- G- H-l) in morphotype 2 and (A — B- (C + D) — E-
G- H- I) in morphotype 3, morphotype 2 did not show group E. Group F did not exist in

12 Akli-Bidi S

all morphotypes, intercoxal plate with dense setules, in all morphotypes, but in
morphotypes 2 and 3, setules are two times longer than those in morphotype 1. On
body of plate, | found two groups of little setules and spinules in morphotype 1, two
groups of little spinules in morphotype 2 and one group of little setules in morphotype
3. Caudal setae had dense long setules, but those of morphotypes 1 and 3 had a
strong spine.

Distribution

This taxon was discovered in the mid-nineteenth century in a pond at Peterhof close to
Saint Petersburg, Russia (Fischer 1851). In recent years, the distributional area of the
species was revised and restricted to a Palearctic distribution. Previous data on
geographical distribution of the species outside this area are critically analysed. It is
hypothesised that records of E. serrulatus from Japan, Australia, North America and
other zoogeographical zones could be a result of recent invasions, possibly via human
activities in relation to ship transport.

Ecology

Freshwater species (lakes, basins, ponds, wadis)

Taxon discussion

Eucyclops serrulatus (Fischer, 1851) has been reported from waterbodies around the
world and, consequently, it has long been considered a cosmopolitan species until
some species that look like Eucyclops serrulatus were separated from it. Some of
these may indeed be valid species; others were forms of Eucyclops serrulatus.

Discussion

In Algeria, | identified three morphotypes belonging to Eucyclops serrulatus group that
differ from the description of Eucyclops serrulatus from the type locality in the
microcharacters of the antennary basipodite and of the P4 coxopodite. The characters of
the most widespread morphotype (morphotype 1) were stable in all localities despite the
fact that these were located in two geographically separated regions (eastern and western
Algeria)

In twenty-one localities, | did not find Eucyclops serrulatus, while this species has already
been mentioned in Algeria by Roy and Gauthier (1927).

In a comparison with other species of Eucyclops serrulatus group from North Africa, |
considered Eucyclops serrulatus hadjebensis (Kiefer, 1926), but this latter is characterised
by a shorter serra.

Eucyclops agiloides (Sar, 1909) was recorded in Algeria by Defaye et al. (2010). These
morphotypes (at least for morphotypes 2 and 3) cannot be attributed to this species, due to

Description and distribution of three morphotypes of the Eucyclops serrulatus ... 13

the lack of long hair-like spinules in position 1-2 on the posterior surface of antennary
basipod; also the "serra" on caudal rami is completely different. P4 intercoxal plate bears
long hair-like spinules in these morphotypes, but it is short in Eucyclops agiloides. There
was ornamentation of P4 coxopodite with 20-21 spinules (C+D) in this species, but with
eight spinules in the morphotypes.

These morphotypes did not cohabit and presented important differences in morphological
characters and microcharacters; they could be ascribed to new pseudocryptic species of
the Eucyclops serrulatus group, which is in need of urgent revision.

Acknowledgements

The author is grateful to Professor H. Dumont for welcoming me in his laboratory and to
Doctor S. Maas for her courtesy and help to confirm the species identification. | thank
Professor L. Beladjal, Department of Biology, Ghent University for English translations.

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